- Abstract -

The use of Co-Cr alloys is traditionally carried out by casting, but it can also be done by using the CAD/CAM system. An alternative is the use of the laser sintering technique. By means of a laser, using a well-established energy/local surface unit, the fine alloy powder used is locally sintered in order to form the prosthetic element. The ST2724G alloy used consists of 64-67% Co, 28-30% Cr and 5-6% Mo, and has the balance of a γ monophasic structure. Mechanically, the breaking limits of the metalo-ceramic elements resulting from this technique are comparable to metalo-ceramic elements obtained by classical casting. The metallographic observations show a slight porosity in the horizontal sample (compared to the sintering plane), while in vertical sample, the pore lines are uninterrupted. The chemical attack shows, just like on the surface, a very fine layered structure roughly corresponding to the original granular structure of the base powder. Punctual analysis shows a high regularity of the local chemical composition. The laser sintering technique makes possible the manufacture of extremely accurate prosthetic elements with mechanical properties that correspond to any clinical requirement.

 

Key words: laser sintering, ST2724G alloy